US Patent 1,996,796, granted 9 April 1935 to Henry Dreyfus, William A. Dickie and William I. Taylor, assignors to Celanese Corporation of America. It describes making artificial filaments, yarns or threads with a regular, systematic variation in denier by varying the output of the spinning pump, using a pawl-and-ratchet drive with cam control or a multi-cylinder cam-driven pump. The text notes use of the resulting yarns in weaving, knitting, braiding and lace-making, and the effects when dyed. It includes two sheets of apparatus drawings and two claims.